Philips Efficia DFM100 - Lead Selection; Lead Choices

Preparing to Monitor ECG 4: ECG Monitoring
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For accurate V/C lead placement and measurement, it is important to locate the fourth intercostal
space.
 To locate the fourth intercostal space:
1 Locate the second intercostal space by first palpitating the Angle of Lewis (small bony
protuberance where the body of the sternum joins the manubrium). This rise in the sternum is
where the second rib is attached, and the space just below this is the second intercostal space.
2 Palpate and count down the chest until you locate the fourth intercostal space.
Lead Selection
It is important to select a suitable lead for monitoring so that a QRS complex can be accurately
detected.
For non-paced patients:
• QRS complex should be tall and narrow (recommended amplitude > 0.5mV).
• R-Wave should be above or below the baseline but not biphasic.
• P-Wave should be smaller than 1/5 R-wave height.
• T-Wave should be smaller than 1/3 R-wave height.
NOTE: To prevent detection of P-Waves or baseline noises as QRS complexes, the minimum detection level
for QRS complexes is set at 0.15 mV, according to AAMI-EC 13/YY1079 specifications. If the ECG
signal is too weak, you may get false alarms for asystole.
For paced patients with internal/transvenous pacemakers:
• Confirm paced status is set correctly on the Efficia DFM100, see “Entering Patient
Information” on page 41.
• All four criteria for non-paced patients listed above.
• Large enough to be detected (half the height of the QRS complex), with no re-polarization
artifact. Some unipolar pacemakers display pace pulses with re-polarization tails which may be
counted as QRSs in the event of cardiac arrest or other arrhythmias. Choose a lead to minimize
the size of re-polarization tails.
NOTE: Adjusting the ECG wave size on the display does not affect the ECG signal which is used for
arrhythmia analysis.
Lead Choices
Available monitoring leads vary depending on what type of ECG cable is connected to the Efficia
DFM100 and its configuration. See Table 5.
To select leads to display on the Efficia DFM100, see “Selecting the Waveform” on page 53.
WARNING: Avoid touching monitoring electrodes and other measuring devices when they are applied to the
patient. Doing so can degrade safety and may affect results.
Table 5 Lead Choices
If you are using These leads are available
a 3-Lead ECG set I, II, III
a 5-Lead ECG set I, II, III, aVR, aVL, aVF, V